Right now, I have three B&B boats. A CS 17, a CS 17 mk 3 and a Marissa 18. All are on galvanized trailers but with different configurations.
I will cover them in chronological order.
I finished my CS 17 'Lively' in 2007 and bought a tilt trailer because I had one on my previous O'Day Daysailer II and really liked it. Occasionally I launch from the beach and the tilt seems to help. When launching/retrieving from a ramp, I never put the wheel hub in the water. I think the wheels are 14" but not sure. The wheels are under the boat so it is higher but this has never been a problem launching. When I got the trailer I moved the winch post forward as far as possible and then moved the wheel/axels forward until I got about 10% tongue weight. I have never had a problem with towing with this combination. I have rollers in the center and a bunk on each side. I need to change out the carpet for Starboard one of these days but it is just not needed. The overall length of boat trailer and masts mounted on top fit in one side of my two car garage with only a slight angle required. When towing the tilt mechanism causes a slight movement of the boat and some extra noise and a wearing of the hull where the bow meets the winch post roller. I still have not figured out how to stop this yet. This is my favorite trailer boat combo.
I finished my Marissa 'Salty' in 2012. I bought a standard galvanized motor boat trailer for and 18' boat. I moved the wheels using the same process as for 'Lively' with 10% tongue weight. The trailer has been fine. I have found that I do not use the boat very much. I am a sailor. However, my son does use and love both boat, motor and trailer. So I keep it for him, for the time being.
Earlier this year, I bought Chick's CS 17 mk 3. We met near Savannah, GA and I drove my new boat home to Palm Harbor, FL. His trailer is huge compared to both of my other trailers. The boat sits between the wheels and is therefore lower and easier to get in and out of. The boat/trailer handled very well on the trip down here and in all the times I have used it here. I did not mention above, my tow vehicle is a 4 cyc Sabaru Forester. I do wet launch (hubs wet) this boat. No bearing problems yet. Watching them. Chick had rollers in the center and vertical bunk boards that he cut to conform to the hull. This is another reason that I launch wet. I like the flat bunks I have in the other trailers better. They have two mounting points and then the board flexes to fit the hull. This boat, trailer, tabernacle masts are a total of 25 feet long. This is way too long for a 17 foot boat. I have not quite figured out how to remedy this yet. It will fit in my two car garage crossways with the masts practically hitting the corners. I think the tires are 14 inch but not sure.
Steve, hope I have answered most of your questions. Good luch with your decidsion. My opinion.